Fluid container port structure attaching method



Sept. 2, 1958 E. s. WELCH, JR 2,850,422

FLUID CONTAINER PORT STRUCTURE ATTACHING METHOD Filed Jan. 20. 1955FREQUENCY SOURCE FLUKE) CUNTAENER PSRT STRUCTURE AWAKE-ENG METHOD EdwardSohier Welsh, .lr., Framingham, Mass, assignor to Fenwal Laboratories,ind, nramingham, Mass, a corporation of Niassachusetts Application.lanuary 2t 1955, Serial No. 483,970

2 Claims. (@l. 154-118) This invention relates to the packaging offluids in flexible heat-scalable containers and to methods and means forproviding such containers with initially closed ports for subsequentaccess to and dispensing of the content fluid, as well as to thecontainers so equipped.

More particularly the invention aims to accomplish the stated endsespecially in conjunction with content fluid for which it is desired tomaintain a uniform, ster'de and pyrogen-free condition, such for exampleas parenteral and intravenous solutions. Other objects for the improvedcontainer methods and product of the invention include visibility forthe content fluid through the container walls, and a relativelynon-frangible easily disposable and inexpensive construction for thecontainers.

In the drawings illustrating by way of example the method of and meansfor practicing the invention, together with a typical resultant product:

Fig. 1 shows a completed fluid package including the flexible containerwith closed outlet port and associated piercing connector;

Fig. 2 is a cross-sectional view as for example upon the line 22 of Fig.1;

Fig. 3 is a plan of an area of an outer wall of the container includingthe outlet;

Fig. 4 is a view corresponding to Fig. 2 illustrating the outlet-formingmethod of the invention; and

Fig. 5 is a plan of an electrode element useful for the method of Fig.4.

Fluid containers formed of heat-sealable plastic sheeting are known andhave come into commercial use within the last few years. Such containersare fabricated either by rolling a flat section of the plastic sheetinginto tubular form and uniting it by a longitudinal heat-applied seam orweld, by superimposing two layers of plastic sheeting and uniting themsimilarly to form either single or plural container units, or byinitially extruding or otherwise molding the plastic material in theform of a seamless tube.

It is also known to fill relatively long or indefinite lengths of suchplastic tubing, whether of the flat-formed or the seamless type, withthe fluid to be packaged, and then to bring together and seal to eachother the opposite walls of the tube across longitudinally spacedtransverse zones, as by applying dielectric heating at the desiredspaced intervals. This in effect divides the initial tubular sectioninto hermetically sealed units each containing the fluid. Such sealedunits may then be separated by cutting them apart centrally across thetransverse heat-sealed zones. Such items as liquid soap and oil haverecently been packaged in this manner. The user cuts or punctures someportion of the unit container wall to let out the content fluid.

Heretofore, however, no satisfactory provision has been made so far as Iam aware for obtaining access to the fluid content of a flexible plasticcontainer of the stated type, identified herein as collapsible, in suchmanner that neither the installation of the outlet means ice 2 in thecourse of completing the fluid package nor the subsequent release of thecontent fluid at the time of use shall in any manner contaminate orobjectionably modify it. The desirability of the collapsible flexibleplastic container for example in the medical and surgical field has beenrecognized, particularly under the increasing demand for commerciallyprepared parenteral, intravenous and other solutions. These obviouslymust be held in a sterile, pyrogen-free and uniform condition. And inmost cases the fluid content must be deliverable from the package so asto flow in well-defined sealed sterile channels as for instance throughfilter and flow indicating devices and through flexible tubing to anintravenous injection medium.

In accordance with the present invention methods and means are presentedproviding for the removal of such fluids from the sealed collapsibleplastic containers through the medium of the attachment of a coupling orexit tube to the outside surface of each container after introduction ofsome fluid content, either partly or wholly filling the container, andin such manner that the container wall may subsequently be puncturedwithout loss or contamination of the fluid content. Such attachment maybe made either before or after sealing ofi unit packages.

In the drawings, filled or partially filled unit containers or packagesof fluid are designated generally at 6 Each comprises a collapsiblecompartment-forming wall F of flexible and preferably transparent ortranslucent plastic sheet material. Such bag-like container 6 may beformed in any known or preferred manner as already mentioned. In theexample of Fig. 1 it may be assumed that the container wall 7 is of theseamless tubular construction having the wall material at the respectivetransverse ends brought together and united as by heat sealing asindicated at 8 and 9 respectively, or as noted it may be formed byuniting layers of plastic sheeting. In the corresponding sectional Figs.2 and 4 fluid content is indicated at 10. Such fluid 10, in the case ofpackages of parenteral, intravenous and other solutions requiring asterile pyrogen-free and uniform use standard, as for medical, surgical,hospital and like uses, may be entered into sterile lengths of thetubular well element and the latter sealed ofi dielectrically into unitpackages at appropriately spaced transverse zones, also in the known orpreferred manner described. It will be un derstood that the plasticsheet material desirably is selected for suitable capacity to withstandheat or other sterilizing treatment subsequent to filling and closingoif of the unit packages should such be desired. Also as mentioned thesealing off into package units may be accomplished after providing theporting means as herein concerned.

Heretofore such filled collapsible containers, bags or pouch-likepackages have lacked provision for sterile access to and dispensing ofthe fluid content. The reasons for this are several. In the use ofdielectric heating for bonding together two pieces of plastic material,that art has heretofore regarded it as essential that metallicelectrodes be placed directly in contact with or close to the externalsurfaces of the plastic members of which the juxtaposed faces are to beinter-bonded. Heating and consequent sealing together or welding takesplace by reason of the electric field created at all areas between theopposed electrodes, these latter being connected to a high frequencysource such as indicated at S in Fig. 4.

Assuming for example it is desired to provide an outlet or other portelement such as designated generally at 12 in Figs. 1 to 4 comprising atube portion 13 and a radial attaching flange 14. Such flanged portingtube 1?. might be placed against the outer face of the container wall 7and an annular or other electrode E, Figs. 4 and 9 5, may be engagedwith the outer face of the tube flange 14. but where indefinitecontinuous lengths of plastic container-forming tubing are to be filledor partially filled before attachment of tubes and either before orafter being sealed oil into unit packages, it is impractical if notimpossible to insert an opposite metallic electrode to the appropriatelocations within the tubing. If on the other hand an effort is made toheat-sealin place a flanged tube without fluid content in the unitpackages, by collapsing together opposed areas of the tubing wall andplacing the metallic electrodes in opposition at the outside faces ofthe juxtaposed wall portions, then the opposed portions of the containerwall 7 themselves be come bonded together at the same time that the tubeflange 14 is installed, with the result thatthe proposed. containerunits are rendered inoperative and useless.

In accordance with the method of the present invention the collapsibletubular container units 6 are supplied with at least a partial liquidcontent 10. The units may be completely filled and sealedotf into unitpackages or the liquid may be limited to that necessary to preventbonding together of opposite walls 7 of the collapsible container 6,complete filling and unit sealing beingsubsequent to the attachment ofport tubes. Thusin carrymg out the method the content liquid 10 isitself availed of as the means for the necessary holding apart or spacr.

Cir

ing of the container walls 7, as against the closing or collapsing forceapplied to the electrode E in engaging the tube flange .14 against thecontainer wall 7.

Referring now more particularly to Fig. 4 illustrating the novel processof installing a flanged port tube 12,,

the tubular wall 7 of the container or package unit '6 18 shownseparated diametrically by the liquid 10 throughout the cross-sectionalarea and particularly at the region 10E where the flanged tube 12 is tobe applied.

. With the tube 12' placed against the outer face off container wall 7wherever it is desired to be located asfor example centrally near oneend of thecontainer,

an annular metallic electrode E is superimposedflatwise upon the outerface of the associated flange 14, Another metallic electrodeE' of plateor disc form and of'cal.

culated or substantially greater area is placed at the.

outer face of the diametrically opposite portion of the container wall7, while making sure that the liquid volume 10 is located or confinedbetween the wall por-j tions 7 having the metallic electrodes E, E5installed thereat. The respective metallic electrodes E, E are connectedas by the leads L and L to any suitable high frequency source S. V

The electric field established between the metallic electrodes E and Eis divided between two layers 7a and 7b of the container wall material7, the volume of the liquid 10 between said wallareas 7a, 7b, and thethicknesses of the flange 14 of the port tube 12. It will be appreciatedthat it is permissiblefor the content liquid 12' to have either a veryhigh resistivity along with high dielectric constant, as when thecontainer fluid is distilled water, or sugar and water, or a lowresistivity, such as it would have in the case of a salt and watersolution. All. that is required is a low impedance by virtue of highdielectric constant of the solution. Likewise the impedance of thecontainer wall area 7b contiguous to the electrode E is low because, asmore or less diagrammatically indicated in Fig. 4, the area of saidelectrode E is made substantially larger than that of the oppositedistal metallic electrode E.

Consequently a considerable fraction of the voltage of the electricfield occurs within the flange 14 of the tube 12 and the herein top wallportion '7a of the containe'n. causing these to be heated to theappropriate bonding temperature without heating any other portion of thesystem to disadvantage. In this connection the interposed liquid 10 isseen not only to space and prevent interbonding of the opposite innerfaces of the container wall. areas 7a and 717 but also, in that it isemployed as a capacitor, acts at the same time as a cooling agent. a forthe non-sealing face of the plastic Wall while the.

latter is being internally heated to bonding temperature especially atthe interface 16, Fig. 4, between the container wall 7a and the flange14 of the tube 12. Thus the liquid volume 10 not only suppliesaconvenient means for application of an electric field to the plasticmaterial but at the same time has the advantage of keeping the containerwall from distorting or from rupturing by becoming unduly thinned ormelted through the application of the tubular port element 12.

From the foregoing description in connection with the drawings it isevident that an important feature of the method and the resulting novelproduct thereof lies in the effective use of a liquid capacitor for theapplication of dielectric heat sealing. It will be evident that thismethod is especially advantageous in the avoidance of progressiveinsertion of a metallic electrode between the Walls of a tubular plasticcontainer. Such procedure, in addition to being extremely diflicult as amechanical operation would be a source of biological contaminationwhereas the substance of the liquid electrode as herein contemplatedgenerally must be filtered and pre-sterilized in any event beforeloading into the container. Another important advantage attendant on themethod of the invention is that the container'wall 7 may be left un portas a whole from contamination and physical damage before ultimate use.

In the foregoing description the invention has been disclosed withreference to containers and port tubes'assumedas being of fuse-bondablethermoplastic material. The invention is equally applicable to theprovision of similar tubular porting installations where the container,pack or hag element, or the flanged tube-element to be applied, or bothsaid elements, and at least at theiropposed or engaged faces, are of amaterial, not thermoplastic or thermoplastic only at excessivetemperatures. 'In such instances the appropriate contiguous surfaces ofthe 'con tainer or the tube or both of them are coated with athermoplastic or other adhesive such thatapplication of the dielectricmeans as herein disclosed will'eflfect-the bond, immediately and asalready herein described if the adhesive is thermoplastic or byaccelerating the setting of the adhesive material if of a thermalsettingor of a solvent type.

Inthe illustrative example of the drawings the corn-' pleted liquidcontainer or package 6 is represented in Figs. 1 and 2 as includingwithin. the tubular portion 13 of the port tube 12 a tubular couplerv20' h'aving atight fit in the tube portion 13 and provided at the innerend with a wall-piercing point. 21, Fig. 2. The outer end portion of thecoupler 20, shown broken away, maybe formed for ready connection toflexible tubing or the coupler may be constituted as an integral portion of such tubing and may be of metal, plastic or other composition.It may be included as an initial element of the completed package ormaybe omitted as circumstances dictate. It

will be apparent that access to the fluid content 10 may i be had bymerely thrusting the pointed end 21 of the cou-,

pler 20, after attachment of the tubing thereto if not integral with it,through the diaphragm-like closure 'portion 7d of the container wall 7defined 'within the base of the tube 12 centrally of the attachingflange 14.-

My invention, either as to product or method, is not limited to theexemplary embodiment or steps herein illustrated or described, and I setforth its scope in my following claims.

I claim:

1. The method of dielectrically bonding a flexible thermoplastic portelement to a flexible thermoplastic liquid storing container havingliquid sealed in it and the Wall of which container presents aheat-bendable external area which comprises positioning the element inbondable engagement externally with an imperforate heat-bondable area ofone wall of the container, applying a metallic electrode to the element,locating a volume of container liquid in juxtaposition to the elementand electrode, applying a second substantially larger metallic electrodeexternally to an imperforate area of the other wall of the containeropposite the liquid volume and with the latter defining a column betweenthe two wall areas, and connecting the metallic electrodes to a highfrequency electrical source.

2. The method of dielectrically heat sealing a flexible thermoplasticliquid dispensing outlet to a flexible thermoplastic liquid storingcontainer which comprises placing the outlet against a continuous areaof a wall of the container, superimposing a metallic electrode on theoutlet, applying a substantially larger metallic electrode to a wallarea of said container opposite said outlet, connecting said electrodesto a high frequency electrical source so as to impress a heatingelectric field on said outlet and container, and locating the fluidstored in said container to provide a column of the liquid internallybetween said wall areas as a liquid capacitor in said field and to spaceand cool said container walls.

References Cited in the file of this patent UNITED STATES PATENTS500,773 Perelli-Minetti July 4, 1893 1,084,944 Leonard Jan. 20, 19142,298,037 Crandell Oct. 6, 1942 2,407,833 Iablonsky Sept. 17, 19462,677,459 Ritzenberg May 4, 1954 2,770,272 Morrison Nov. 13, 1956

1. THE METHOD OF DIELECTRICALLY BONDING A FLEXIBLE THERMOPLASTIC PORTELEMENT TO A FLEXIBLE THERMOPLASTIC LIQUID STORING CONTAINER HAVINGLIQUID SEALED IN IT AND THE WALL OF WHICH CONTAINER PRESENTS AHEAT-BONDABLE EXTERNAL AREA WHICH COMPRISES POSITIONING THE ELEMENT INBONDABLE ENGAGEMENT EXTERNALLY WITH AN IMPERFORATE HEAT-BONDABLE AREA OFONE WALL OF THE CONTAINER, APPLYING A METALLIC ELECTRODE TO THE ELEMENT,LOCATING A VOLUME OF CONTAINER LIQUID IN JUXTAPOSITION TO THE ELEMENTAND ELECTRODE, APPLYING A SECOND SUBSTANTIALLY LARGER METALLIC ELECTRODE